Technical Field
The present invention relates to an image evaluation device, an image evaluation method, and a program storage medium.
Related Art
There is a case in which part of printouts printed by a printing machine are defective printouts. Therefore, an inspection method of determining the quality of a printout is proposed, in which images are obtained by scanning and reading printouts, and determination is made as to whether or not there is an image of defective printouts that cannot be ignored in the read images (for example, see Japanese Patent Application Laid-Open (JP-A) Nos. 2007-033247 and 2006-139777).
JP-A No. 2007-033247 (Japanese Patent No. 4407588) discloses an inspection method that determines whether or not a defect included in a scanned image of an inspection object is acceptable by calculating a density difference between a master image for output and the scanned image of the object to be inspected and determining whether or not the calculated density difference is allowable.
JP-A No. 2006-139777 discloses a method of detecting a surface non-uniformity in a flat panel display using a visual model. This method includes recognizing a taken image of a test panel and a reference image that is simulated by a background by a difference recognition system, and evaluating the quality of the display using a visual model.
When an image included in a printout is read for the purpose of detection by a device such as a scanner, there is a case in which the obtained image (an image for detection) includes a defect in a line form (hereinafter, referred to a “line defect”). The line defect is caused by, for example, a problem such as a structural problem of the printing machine. Further, most of line defects caused by the problem of the printing machine tend to appear in a line form along a specific direction. The degree of this kind of line defect often exceeds an acceptable range.
However, the methods disclosed in the above documents do not provide an accurate determination of whether or not a line defect caused by the structural problem of the printing machine is an inacceptable line defect.